#ifdef PPP_SUPPORT
#include "ppp_device.h"
int ppp_device_attach(struct ppp_device *ppp_device, const char *uart_name, void *user_data);
struct ppp_device *ppp_air720_register(void);
class ppp_class
{
public:
    ppp_class(){};
    int begin(HardwareSerial *serial)
    {
        device = ppp_air720_register();
        device->uart = serial;
        if (ppp_device_attach(device, "PPP_CLIENT_NAME", 0) != 0)
        {
            core_debug("ppp_device_attach execute failed.");
            return -1;
        }
        return 0;
    }
    int end(void)
    {
        if (ppp_device_detach(device) != 0)
        {
            core_debug("ppp_device_detach execute failed.");
            return -1;
        }
        return 0;
    }

private:
    struct ppp_device *device;
};
#endif